Placing two or more electrical circuit boards perpendicular to each other is an arrangement which may be attractive in order to save space. Interconnection of electrical circuit boards placed adjacent but perpendicular to each other can easily be done by means of flex foils in a cost effective way.
U.S. Pat. No. 3,281,627 discloses an insulative panel having a plurality of signal conductors supported on a side of the panel, the signal conductors terminating adjacent an edge of the panel. A first set of holes is formed in the edge surface of the panel, each hole of the first set corresponding to one of the signal conductors. A second set of holes is formed in the insulative panel at a distance from the edge surface, each hole of the second set intersecting a signal conductor and the corresponding hole of the first set. A coating of conductive material is deposited on the walls of each hole. The coated holes of the first set serve as female connectors which are adapted to receive male connector pins. US 2010/0062621 A1 discloses a horizontal dual in-line memory modules. The memory module includes a circuit board, a plurality of memory chips attached to a top surface of the circuit board, and a plurality of courrector contacts disposed under a back surface of the circuit board and extending away from the memory chips, the connector contacts being electrically coupled to the memory chips, the back surface opposite the top surface of the circuit board.
DE 10 2004 063135A1 discloses a printed circuit boards which are interconnected by means of flexible strip conductors or jumpers. The jumpers are soldered to the circuit boards in one step along with other SMD components and other components in a reflow soldering furnace. Metal-plated lateral openings are mounted in the face of the circuit board, which is usually provided with several inner layers as well as inner strip conductors and outer strip conductors. Terminal pins or connecting wires of a jumper that are plugged into said openings can be soldered to the circuit board together with other components in a reflow soldering furnace after introducing or applying solder paste.